Knifehead is a Category III Kaiju.
Large and bulky, Knifehead is a heavily built Kaiju. Its most notable feature is the long and broad sharp-ended nose, that could easily cut through the armor of a Jaeger. Atop the center of its head resides a blowhole that forcefully expels air whenever it resurfaces from the water. It has a large shell-like armor on its back, while the rest of its body is similar to a goblin shark in appearance.
Knifehead possesses two large dominant arms and two smaller secondary arms protrude from its belly. Its large arms each have three clawed digits, the middle digit being significantly larger. Bright yellow lines run through a pattern across its body, with the rest of its body being a dark grey. Its eyes and the interior of its mouth, however, glow blue.
Like Slattern, Trespasser, and Scunner, Knifehead's primary forearm bones have a fleshless gap between them, looking like two fused arms ending in three-digited claws. Knifehead is the largest Category III Kaiju recorded so far, topping fellow Category III Kaiju Yamarashi's record.
Knifehead emerges from the Breach and heads for Anchorage, Alaska. In a move to head the creature off, Romeo Blue is deployed to defend the ten mile mark. However, Knifehead evades the Mark-1 Jaeger. Gipsy Danger, piloted by brothers Raleigh and Yancy Becket, is deployed from the Anchorage Shatterdome Jaeger base to defend the Miracle Mile. As it approaches the city, swimming on the surface at night during a violent storm, it encounters the fishing boat Saltchuck. The beast is so large that the crew initially mistake it for an island. They realize it is in fact a Kaiju when their radar shows the "island" rapidly approaching them.
The Kaiju rises from the water and advances on the Saltchuck to attack it. But it is interrupted by the arrival of Gipsy Danger, when it rises from the water aft of the Saltchuck. The Jaeger picks up the boat and deposits it out of harm’s way as Knifehead attacks it.
Knifehead receives a right and a left uppercut from Gipsy Danger, followed by a two-handed smash to the top of its head from the Jaeger’s fists. It lunges as Gipsy Danger raises its left arm defensively, catching the arm in its teeth. Gipsy Danger pushes forward and shakes the beast off, then fires three blasts from its right arm’s Plasmacaster into the Kaiju’s chest. Knifehead falls backward the water and sinks out of sight, apparently dead. At the Anchorage Shatterdome’s LOCCENT, its signature vanishes.
The Becket brothers congratulate themselves on their fifth Kaiju kill. But at LOCCENT, Knifehead’s signature reappears. The Rangers are warned, but the warning is too late. Knifehead explodes out of the water at Gipsy Danger, slashing and snapping at its Conn-Pod. Struggling to keep its jaws away, the Rangers charge and aim Gipsy Danger's left arm Plasmacaster to again shoot the beast. Knifehead reacts, pulling the arm aside. It then plunges its blade-like snout into Gipsy Danger’s left shoulder and rips the arm off.
With a roar, Knifehead sinks its claws into Gipsy Danger's Conn-Pod and tears off a large section of the cockpit’s right side, taking Yancy with it to his death. The Kaiju continues its relentless assault, plunging its snout through Gipsy Danger’s chest as it thrashes the Jaeger, then it sinks its teeth into the remains of Gipsy Danger's severed left shoulder and savagely tears at it. As Knifehead grapples with the Jaeger, Raleigh, straining with the effort of operating Gipsy Danger by himself, charges and fires the right arm's Plasmacaster point blank at the Kaiju's face. Knifehead is killed by the shot.
The engagement between Knifehead and Gipsy Danger marks a turning point in the Kaiju War. In all previous battles, the Kaiju had been unthinking brutes, easily defeated by the intelligence, weaponry and tactics of the Rangers and their Jaegers. Knifehead is the first Kaiju to display overt intelligence and cunning. Subsequent engagements over the next five years demonstrate the beasts' increasing power, intelligence, and ability to adapt to the Jaegers weapons and their pilots’ tactics.
- Knifehead was the first Kaiju created by Industrial Light and Magic.
- Scunner and Knifehead use the same basic CG body as Trespasser in Pacific Rim.
- In Pacific Rim: Tales From Year Zero, Knifehead's skull can be clearly seen mounted on the room, and in the next page Gipsy Danger's damaged body.
- According to Man, Machines & Monsters Knifehead weighs 2,700 tons. In the film, Knifehead 8,700 metric tons.
- Knifhead bears a strong resemblance to Guiron, a kaiju from the 1969 film Gamera VS Guiron. It's possible that Knifehead's design is a homage to Guiron.
- A 7" Knifehead figure is part of Series One of NECA's Pacific Rim collectible figures.
- Several identical copies of Knifehead can be seen in the Precursors processing facility (hundreds in concept art of the film). This hints at the idea that there were to be many attacks from this Kaiju type, or that it was a basic kaiju template.
- Knifehead appears in Pacific Rim: The Video Game.
- A larger Deluxe figure of Knifehead was released in Series 3 of NECA'S Pacific Rim line. This version is 1.5 times the size of the Series 1 Knifehead and feature more articulation as well as a battle damaged paint scheme with Kaiju Blue.